Mirjana Lucic-Baroni has spent 15 years in the tennis wilderness since reaching the Wimbledon semi in 1999.

US Open, Flushing Meadows, New York

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Mirjana Lucic-Baroni described her US Open victory over world number two Simona Halep as "the best day of my life", and with good reason.

The 32-year-old Croat won 7-6 (8-6) 6-2 to reach the fourth round at Flushing Meadows as a qualifier.

Remarkably, the last time she reached the final 16 at a Grand Slam tournament she beat Monica Seles on her way to the semi-finals, where she lost to Steffi Graf.

That was at Wimbledon 1999, and since then Lucic-Baroni has endured a torrid time away from the court.

"I'm a little bit emotional now, sorry," she said tearfully after Friday's win at Flushing Meadows.

"It's been really hard. After so many years to be here again, it's incredible. I wanted this so bad.

"So many times I would get to a place where I could do it. Then I wanted it so bad that I'm kind of burned out. And I apologise again. Yeah, I'm so happy."

Match stats

Mirjana Lucic-Baroni

Simona Halep

Match time: 1hr 34 min

3

Aces

4

6

Double faults

7

52

1st serve %

58

67

1st serve win %

54

53

2nd serve win %

40

31

Winners

17

36

Unforced errors

23

5/10

Break points won

3/8

Lucic-Baroni was a tennis prodigy, winning junior Grand Slam titles in the US and Australia before making her senior Slam debut as a 15-year-old at the 1997 US Open.

She also won her first senior tournament aged 15, along with a Grand Slam doubles title partnering Martina Hingis in Australia.

Her career seemed to be on an unstoppable rise when she made that breakthrough at Wimbledon aged 17, but alleged physical and verbal abuse by her father, Marinko, had already led to her fleeing Croatia for the US with her mother and siblings.

With little money and support, Lucic-Baroni slipped down the rankings to such an extent that between 2004 and 2006 she played just three matches.

"It's really uncomfortable for me to talk about it," she said. "It wasn't any lack of desire or anything. It's just circumstances were such.

Lucic-Baroni won 75% of the points she played at the net, while Halep lost all of her net points

"I still played with my brothers a lot. I was still in tennis a lot. I was still waiting for my opportunities and things like that."

Lucic-Baroni has guaranteed herself US$187,300 (£112,812) with six wins in the last 11 days, just over 10% of her entire on-court earnings in a career that began 17 years ago.

And she can now set her sights on a second Grand Slam quarter-final, 15 years after her first, with Italian 13th seed Sara Errani standing in her way.

"I feel goofy right now," said the Croat. "I feel like I'm 15. I feel so excited. It's crazy. I'm 32, but I don't feel like that.

"My body is really great. That's really important. I feel fit. I feel strong in my mind. I feel very excited, even after so many years on tour.

"I have such an amazing husband and such a happy life at home that I don't need to do this, you know. I would be perfectly fine having a family.

"But people don't realise how much I want this and how hard I worked for this.

"It's these moments in these last two weeks that are what I work for. It's just so fulfilling, so amazing."

Halep's first serve speed was 97mph, compared to Lucic-Baroni's 102mph